によって Abigail Long 5年前.
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kepler's 2nd law- a line that connects planet's to the sun that sweeps out equal times and equal areas.
Hydrogen-a colorless, odorless, highly flammable gas, the chemical element of atomic number 1. Helium-the chemical element of atomic number 2, an inert gas which is the lightest member of the noble gas series.
Subtopic
Radiation cooled the microwaves because the universe expanded, static because there was so much energy released, and leftover radiation from the big bang.